Partitioning characteristics of gas channel of coal-rock mass in mining space and gas orientation method

• Published in: International journal of mining science and technology 2013-11, Vol.23 (6), p.873-877
• Main Authors: Zhao, Zhiqiang, Ma, Nianjie, Jia, Housheng, Cheng, Yuanping
• Format: Article
• Language: English
• Subjects: Channels; Fluid flow; Gas channel; Gas flow regime; Gas orientation method; Mathematical models; Mining; Orientation; Partitioning characteristics; Rock; Turbulence; Turbulent flow
• ISSN: 2095-2686
• DOI: 10.1016/j.ijmst.2013.10.014

In order to research the influence of coal-rock mass morphology of mining space on the flow law of gas, the laboratory physical model and numerical computation methods were adopted to simulate coal min-ing activities. The simulation results indicate that, after coal seam mining, the loose rock accumulation body of free caving, ordered rock arrangement body of plate damage rich in longitudinal and transverse fractures and horizontal fissure body formed by rock mass deformation imbalance are formed from bottom to top in the mining space. For these three types of accumulation bodies, there are essential differences in the accumulation state, rock size and gas breakover characteristics. According to this, the coal-rock mass in the mining space is classified into gas turbulence channel area, gas transitional flow channel area and gas seepage channel area. In the turbulence channel area, the gas is distributed trans-versely and longitudinally and gas diffuses in the form of convection with Reynolds number Re more than 100;in the transitional flow channel area, one-way or two-way gas channels are crisscross and gas is of transitional flow regime with Re between 10 and 100. In the seepage channel area, there are a few vertical gas channels with Re less than 10. In this paper, the researches on the gas orientation method in different partitions were further carried out, gas orientation methods of low-level pipe burying, middle-level interception and high-level extraction were determined and an on-site industrial test was conducted, achieving the effective diversion of gas and verifying the reasonableness of gas channel partition.